Add authenticityToken directive.
Remove the authenticity-token directive definition from the ProblemForm module and just import the directives module.
Submissions#create can create a list of submissions now.
Add button to submit answers for all tasks.
Ensure the input is a string for InputParser.
Implement the alerts directive.
Use the alerts directive in problem page.
Properly handle and update data after submission.
Return the problem in JSON for Submissions#create.
Update the problem model after submissions.
Show more info in problem json.
Render more stuff on the problem page using Angular.
Give the problem scores some colors.
Show spinner while submitting answers.